Nasonia is a genus of four insect species that is quickly emerging as a model system, particularly for the genetics of complex traits, development, and microbial-host interactions. It has several features that make it an excellent genetic system. These include ease of handling, short generation time, male haploidy, interfertile species, visible and molecular markers, and a wealth of phenotypes of biological and medical relevance. The form of sex determination, called haplodiploidy, makes Nasonia particularly suited for genetic studies. Females are diploid and develop from fertilized eggs, whereas males are haploid and develop parthenogenetically from unfertilized eggs. This allows geneticists to exploit many of the advantages of haploid genetics in an otherwise complex eukaryotic organism. Furthermore, Nasonia readily inbreeds, permitting production of isogenic lines, and the four species in the genus are inter-fertile (after removal of the endosymbiont Wolbachia), facilitating movement of genes between the species for efficient positional cloning of quantitative trait loci (QTL). Full (6X) genome sequencing of N. vitripennis (Nv) and partial (1X) sequencing of the interfertile species N. giraulti (Ng) and N. longicornis (Nl) is now completed. This genome project provides a wealth of interspecies polymorphisms (SNPs, indels, microsatelites) to facilitate positional cloning. A gene affecting tissue-specific cell growth has already been cloned, and other efforts are underway to dissect the genetic basis of wing-development, embryonic development, parthenogenesis, bacterial-host interactions, host preference, sex determination, diapause, male pheromones, and courtship and reproduction. In addition, systemic RNAi and transformation have recently been demonstrated in Nasonia. We propose to further develop a set of genomic and genetic tools that will allow the research community to exploit more efficiently the particular advantages of this emerging genetic system. Our specific goals are to (a) complete mapping of the Nasonia scaffolds using an efficient array-based approach and interspecies crosses, (b) analyze and develop tools for exploiting the Nasonia transcriptome, (c) Improve RNAi and transgenesis methods and tools, and (d) develop a set of genetic tools to enhance efficient positional cloning. These resources will both improve discovery and cloning of QTL in Nasonia, and its utility to other research systems for comparative genetic and genomic research. The proposed tool development will greatly enhance the Nasonia system as a genetic and comparative model, and allow fuller utilization of the Nasonia genome. It has the strong support of the Nasonia and other relevant research communities.